Procedures

Imaging

CT Coronary Angiography (CTCA)

Computer Tomography (CT) or ‘CAT’ scans are special x-ray scans that produce cross-sectional, highly detailed pictures of the body using x-rays and a computer. A Cardiac CT examines the heart, its arteries and how the heart itself works.

The CT machine looks like a large doughnut with a narrow table in the middle. The table moves through the large circular hole in the centre of scanner. A Cardiac CT requires the injection of iodinated ‘Contrast’. When injected into the bloodstream, contrast enhances the visibility of organs and blood vessels on the resulting images. By highlighting the contrast between the iodinated substance and the surrounding tissues, the organs and blood vessels become more distinct and easier to visualise, thus aiding in the diagnostic process

Will it hurt? Do I need an anaesthetic?

A CT Cardiac Scan is a painless procedure, no anaesthetic is required. The CT machine is open at both ends so patients who are claustrophobic have little difficulty with this test.

Should I do any special preparation?

The partial medical imaging department will give you instructions on how to prepare for your scan. You should continue to take all of your usual medication with some exceptions. Primarily, if you are diabetic and take metformin you should not take it on the day. The radiology practice will ask you to recommence it within 24 hours. Also if you take If you take the following medications Viagra, Levitra, Cialis you are not to take them with 24 hours of the test

In general you are not to eat/drink any foods containing caffeine (tea/coffee, cola drinks, chocolate etc) in the hours leading up to your appointment. You can eat or drug normally prior to the scan and we would recommend you drink water prior to your scan.

If your heart is beating too fast for the scan, you may need to take a tablet (a beta blocker) that will help slow down your heart rate. If you are asthmatic or can not have beta blockers, or have become very wheezy in the past, you must let your referring doctor know and we can commence you on an alternative rate controlling agent.

The scan can not be performed if you are pregnant or breastfeeding without special considerations.

What happens during the procedure?

A needle (IV cannula) will be put into a vein in your arm. This will be used to inject the Contrast.

Your heart rate, blood pressure and oxygen levels will be monitored. If your heart rate has not slowed down enough for the scan you may be given an injection of a beta blocker. You may also be given medication to help open up your arteries.

The Radiographer will not be in the room during the scan, but will be able to see you and communicate with you via an intercom system.

As the x-ray tube rotates around you, you will hear a whirring or humming noise and you will feel the table move slowly through the CT scanner. You should remain as still as possible, as the slightest movement can blur the pictures. You will be asked to hold your breath for up to 20 seconds while the pictures are being taken.

How long does it take?

The actual scan takes about five minutes, but the preparation time can take around one hour. Hence allow around one hour for the procedure to occur. You will be observed for 20 minutes post procedure to see that you are well as all of the medications would have worn off at that point.

What are the risks of this specific procedure?

The main risks and complications with this procedure are associated with the drugs that are used. They can include but are not limited to the following.

Light headedness or dizziness, fatigue and weakness, shortness of breath, headaches, nausea, low blood pressure, dry mouth, blurred vision, and abnormal heart beat.

Other risks and complications of the actual procedure

Common risks and complications include:

  • Minor pain, bruising and/or infection from the IV cannula. This may require treatment with antibiotics.

Less common risks and complications include:

  • An allergy to injected drugs requiring further treatment.
  • The procedure may not be possible due to medical and/or technical reasons.

Rare risks and complications include:

  • An increased lifetime cancer risk due to the exposure to x-rays
  • Cardiac arrest.
  • Death as a result of this procedure is very rare.

What happens if I am allergic to contrast or have renal dysfunction?

Your test will need to be performed within a hospital setting at either Calvary Public Hospital or the Canberra Hospital Radiology Department.